La Colombe, the premium coffee brand backed by billionaire yogurt mogul Hamdi Ulukaya, has hired Moelis & Co. to explore fundraising options, including the sale of a stake in the company.The company is seeking a valuation north of $1 billion and is open to selling a minority or majority stake, according to a person familiar with the matter. La Colombe may also decide to take on outside investors in a bid to fuel growth, said the person, who asked not to be identified because the deliberations are private.